1. Field of the Invention
The present invention relates to an ink jet recording apparatus that records on a recording sheet by ink jet recording means for discharging ink from ink discharge ports. More particularly, the invention relates to an ink jet recording apparatus capable of providing fine undulations in the recording sheet prior to ink jet recording, with the sheet being subjected to deformation when discharged ink is received thereon.
2. Related Background Art
Conventionally, it has been proposed to provide the platen of the ink jet recording apparatus with irregularities, such as disclosed in Japanese Patent Laid-Open Application No. 6-115195, in order to remove wrinkles or undulated deformation (hereinafter referred to as cockling) when ink is discharged onto a recording sheet.
Now, in conjunction with FIG. 15 and FIG. 16, description will be made of the conventional ink jet recording apparatus. The ink jet recording apparatus 100 shown in FIG. 15 is provided with carrier rollers 102 and 103, which serve as sheet conveying means on the upstream side of ink jet recording means 101 relative to the sheet conveying direction, and with exhaust roller 104 and spur 105 on the downstream side of the ink jet recording means.
Also, a platen 106 is arranged in a position to face the ink jet recording means 101. Extrusions 106a are arranged on the upper face of the platen, that is, the surface that faces the discharge port surface 101a of the ink jet recording means. Each of the extrusions 106a is formed on an inclined face which rises in the sheet conveying direction. In this way, it is possible to convey the sheet P in a path following the platen.
With the structure described above, however, recording is performed in a state where the sheet is inclined relative to the discharge port surface 101a of the ink jet recording means 101, because the sheet P follows the extrusions 106a. Thus, the distance in which ink is discharged from the discharge port surface 101a and impacted on the surface of the sheet P varies in the upstream side and downstream side of the sheet relative to the sheet conveying direction. As a result, the impact positions of the ink tend to vary accordingly, thus creating color deviation in some cases.
Also, before and after the sheet P is pinched by the exhaust roller 104 and the spur 105, the distance between the discharge port surface 101a and the sheet changes extremely to make it impossible to perform recording. If recording should be effected on this portion, discontinuation occurs in the recorded images in some cases due to the changed recording condition.
The present invention is designed in consideration of the problems discussed above. It is an object of the invention to provide an ink jet recording apparatus capable of conveying a recording sheet reliably without allowing it to be in contact with the recording head using structure for improving the recording condition and the sheet conveying condition.
It is another object of the invention to provide an ink jet recording apparatus capable of obtaining recorded images in good condition without creating color deviations or the like by maintaining a stable distance between recording means and a recording sheet.
It is still another object of the invention to provide an ink jet recording apparatus using ink to be discharged from a plurality of ink discharge ports of recording means which comprises holding means for holding recording means for recording on a recording sheet; conveying means for conveying the recording sheet; and a recording sheet supporting member arranged in the position to face the recording means which is provided with a supporting surface to support the non-recording surface of the recording sheet, and arranged in the direction intersecting the conveying direction of the recording sheet. The recording sheet supporting member has a first extrusion and a second extrusion extended in the conveying direction of the recording sheet, at the same time, being provided with the inclined surfaces becoming lower to the recording sheet supporting member from the supporting surface toward the upstream side in the conveying direction, and the angles of inclination are different for the inclined surfaces of the first extrusion and the second extrusion.
It is a further object of the invention to provide a recording apparatus provided with holding means for holding recording means for recording on a recording sheet; conveying means for conveying the recording sheet; and a recording sheet supporting member arranged in the position to face the recording means, being provided with a plurality of extrusions to support the upper surface of the non-recording surface of the recording sheet conveyed by the conveying means, which comprises:
a first extrusion arranged for the recording sheet supporting member to support the end portion of the recoding sheet in the width direction; and
a plurality of second extrusions arranged for the recording sheet supporting member to convexly support a part of the recording sheet in the width direction toward the recording means side.
It is still a further object of the invention to provide a recording apparatus provided with holding means for holding recording means for recording on a recording sheet; conveying means for conveying the recording sheet; and a recording sheet supporting member arranged in the position to face the recording means, being provided with a plurality of extrusions to support the upper surface of the non-recording surface of the recording sheet conveyed by the conveying means, which comprises:
a first extrusion arranged for the recording sheet supporting member to support the side end portion of the recording sheet in the conveying direction of the recording sheet;
a plurality of second extrusions arranged for the recording sheet supporting member to convexly support a part of the recording sheet in the width direction toward the recording means side; and
a third extrusion arranged between the first extrusion and the second extrusion.
Other objectives and advantages besides those described above will be apparent to those skilled in the art from the description of a preferred embodiment of the invention which follows. In the description, reference is made to accompanying drawings, which form a part hereof, and which illustrate examples of the invention. Such examples, however, are not exhaustive of the various embodiments of the invention, and therefore reference is made to the claims which follow the description for determining the scope of the invention.